نتایج جستجو برای: apci
تعداد نتایج: 399 فیلتر نتایج به سال:
Methods for the isolation of lipophilic pigments from crude extracts of plant materials (spinach and sweet corn) by high-speed counter-current chromatography (HSCCC) were developed. Particular attention was given to (all-E)-lutein and (all-E)-zeaxanthin. However, the concomitant pigments neoxanthin, violaxanthin and beta-carotene as well as chlorophylls a and b were also considered. Furthermore...
A simple, fast, and sensitive method for the extraction through direct saponification, separation, quantification, and identification of 12 cholesterol oxidation products (COPs) and cholesterol in a single isocratic, normal-phase, high-performance liquid chromatography (HPLC) was developed. Three detectors were compared for determination of COPs and cholesterol in fish samples: refractive index...
Narcissus is widely used for cut flowers and potted plants, and is one of the most important commercial bulbous flowers in the floricultural industry. In this study, ten carotenoid and eighteen flavonoid compounds from the perianths and coronas of fifteen narcissus cultivars were measured by HPLC-APCI-MS/MS and UPLC-Q-TOF-MS/MS. Among these, six carotenoids, a total of seventeen flavonols and c...
An improved analytical method which offers rapid, accurate determination and identification of 22 amino acids in a variety of matrices, e.g. baby foods, juices, honey is reported. The amino acids were extracted from the matrixes using acidified water. Simultaneous determination of 22 underivatized amino acids was carried out by a liquid chromatography-mass spectrometry (LC/MS). A narrow-bore co...
The potential of an advanced analytical strategy based on the use of gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS) with two different analyzers and ionization sources has been investigated and applied to the non-target analysis of food packaging contaminants. Initially, the approach based on GC-time-of-flight (TOF) MS with electron ionization (EI) source allowed pe...
The use of the Agilent LC/MSD TOF, an orthogonal-axis time-of-flight (oa-TOF) mass spectrometer, equipped with an atmospheric pressure chemical ionization (APCI) source, is described for the analysis of four anabolic steroids and one internal standard, in urine extracts at a 1–2 ng/mL concentration. The high degree of mass accuracy (<3 ppm) of the TOF instrument allows for both excellent confir...
trans-Resveratrol and trans-piceid were found for the first time in dark chocolate (at least 0.4 ppm trans-resveratrol and 1 ppm trans-piceid) and cocoa liquor (at least 0.5 ppm trans-resveratrol and 1.2 ppm trans-piceid). Because these compounds are highly sensitive to light, a specific extraction procedure was required to recover them, involving delipidation with toluene and cyclohexane and e...
Numerous plant species worldwide including Palicourea marcgravii and Tanaecium bilabiatum in Brazil cause sudden death and are known to contain monofluoroacetate (MFA). Other species in Brazil including some species traditionally assigned to Mascagnia but now properly called Amorimia species and other Palicourea species are reported to cause sudden death in livestock and are suspected to contai...
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